Boise, Idaho ? In a subdued ending to a week of startling political theater, Sen. Larry Craig announced his resignation Saturday, bowing to pressure from fellow Republicans worried about damage from his arrest and guilty plea in a gay sex sting.

“I apologize for what I have caused,” Craig said, his wife Suzanne and two of their three children at his side with a historic Boise train station as backdrop. “I am deeply sorry.”

Craig, 62, said he would resign effective Sept. 30, ending a career in Congress spanning a quarter-century.

Making no specific mention of the incident that triggered his disgrace in his remarks, he spoke for under six minutes and took no questions.

Among those attending was Republican Gov. C.L. “Butch” Otter, who will appoint a successor for the remaining 15 months of Craig’s term.

It was a relatively quick end to a drama that began Monday with the stunning disclosure that Craig had pleaded guilty to a reduced charge following his arrest June 11 in a Minneapolis airport men’s room.

Craig at first tried to hold on to his position, contending in a public appearance Tuesday that he had done nothing inappropriate and that his only mistake was pleading guilty Aug. 1 to the misdemeanor charge. But a growing chorus of leading GOP leaders called for him to step down to spare the party further embarrassment and possible harm in next year’s elections.

Otter said Saturday he has not chosen a replacement, although several Republicans familiar with internal deliberations said he favored Republican Lt. Gov. Jim Risch.

Otter called speculation that he has made a choice “dead wrong” and declined to say when he would fill the seat.

Craig said he would remain in the Senate until Sept. 30 in hopes of providing a smooth transition for his staff and whoever is chosen as his successor.

President Bush called Craig from the White House after the senator’s announcement and told him he knew it was a difficult decision to make, said White House spokesman Scott Stanzel.

“Senator Craig made the right decision for himself, for his family, his constituents and the United States Senate,” Stanzel said.

Craig was arrested June 11 in a police undercover vice operation. The arresting officer, Sgt. Dave Karsnia, said in his report that the restroom where he encountered Craig is a known location for homosexual activity.

Craig has faced rumors about his sexuality since the 1980s. He has called assertions that he has engaged in gay sex ridiculous.

“I am not gay. I never have been gay,” Craig said defiantly after a news conference Tuesday. He said he had kept the incident from aides, friends and family and pleaded guilty “in hopes of making it go away.”

On Saturday, Craig said he would pursue legal options to clear his name. He has retained Billy Martin, a Washington lawyer who represented Atlanta Falcons quarterback Michael Vick in his dogfighting case, to pursue his legal options.